雄全异株植物瘿椒树(省沽油科)的传粉生物学

Pollination Biology in Androdioecious Species Tapiscia sinensis(Staphyleaceae)

从开花动态、传粉昆虫、花的形态结构、繁育系统、花粉活力和柱头可授性等方面研究了我国特有珍稀植物瘿椒树(Tapiscia sinensis Oliv.)的传粉生物学特性。瘿椒树是典型的雄全异株植物,两性花中含有功能性花粉,且自交亲和,但雄花花粉活力和萌发力是两性花的10倍以上。雄株和两性植株具有相同开花物候期,花期均为5月下旬至6月上旬,单花期为4-5天,雄花和两性花的5枚花药开裂的不同步性明显延长了散粉时间。两性花雌蕊先熟,柱头可授性较长。具有适应风媒和虫媒传粉的花部特征。传粉昆虫主要为蜜蜂科(Apidae)和食蚜蝇科(Syrphidae)昆虫,访花高峰期为8:30-10:30。维持瘿椒树雄全异株的可能机制是:雄株总体上增加了异交花粉的数量和质量;两性花的雄蕊为该物种提供了繁殖保障,同时为传粉者提供了报酬。

The pollination biology of the androdioecious species Tapiscia sinensis was studied by the flowering dynamics, pollinators, morphology and structure of flower, breeding system, pollen viability and the acceptance of stigma of hermaphroditic flower. T. sinensis is a typical androdioecious species with male and hermaphroditic individuals. Hermaphroditic flowers have functional pollen and are self-compatible. Pollen viability from males was more than 10 times higher than that from hermaphrodites. The flowering phonology of both male and hermaphroditic individuals was identical. The duration of flowering was from late May to early June. The anthesis of a single flower could be prolonged to 4-5 d. The stamens appeared to show heterotypical maturation and prolonged the pollen dispersion pedod of a single flower. Hermaphrodites were protogyny, and the stigma had acceptance during the entire anthesis. T. sinensis is a wind- and insect-pollinated species. Insects, such as bees and hoverfly were the main pollinators; the highest visiting time was between 8：30 and 10：30. The maintenance mechanism of T. sinensis species may be as follows： males increase the quantity and quality of pollen for outcrossing, and the stamens of hermaphrodites may assure reproduction and be a reward for the pollinator.